Treatment in the Face of Uncertainty Following Traumatic Anhydrous
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Jill Termaat, MD; Elizabeth Wheatley, MD; Michael V. Bloom, PhD; Treatment in the face of Jerome W. Freeman, MD; Mark K. Huntington, MD, PhD uncertainty following traumatic Center for Family Medicine, Sioux Falls, SD (Drs. Termaat, Wheatley, anhydrous ammonia exposure Bloom, and Huntington); Department of Neuroscience (Dr. Freeman) and The patient lost consciousness and his vision. He then Department of Family Medicine (Drs. Bloom and experienced incomplete sight recovery, anxiety, and Huntington), Sanford School of Medicine, Sioux Falls recurring nightmares. How would you proceed [email protected] with his care? The authors reported no potential conflict of interest relevant to this article. is a previously healthy 33-year-old A month later, an ophthalmologist reex- D white man, married and father amined JD and, again, found no cause for the J of 2 children, who, while working as an ocular abnormality and suggested artificial agronomist, was inadvertently exposed to tears for dry eyes. Two months later, he saw anhydrous ammonia. His only recollection an optometrist, who documented constrict- of the event was a "puff of smoke” and the ed visual fields and referred JD to a second smell of ammonia. He lost consciousness ophthalmologist. This consultant suggested almost immediately and awoke several days possible brain injury and doubted it was psy- later in the intensive care unit. He was blind. chosomatic in nature. He referred the patient Over the days that followed, he regained to a neurologist. The neurologist found no or- central vision; however, the loss of peripheral ganic explanation for his vision loss. He sus- vision in all fields persisted. He said that pected a somatoform disorder and told JD his upon first waking in the morning, he could vision should recover. JD and his wife initially "only see shadows.” For the rest of the day, declined the neurologist’s idea of a neuro- he had “tunnel vision.” Ophthalmology and ophthalmology consultation, but eventually neurology evaluations uncovered no obvious agreed. The neuro-ophthalmologist also sus- reasons for the persistent vision loss. pected a functional disturbance as the cause The patient also complained of mild for visual impairment; and he required the headache and discomfort behind his eyes for patient to stop driving a motor vehicle until which he was taking aspirin. The discomfort his vision improved. behind his left eye was worse than on the The patient was subsequently referred right. He remained on disability following for psychological evaluation. When initially his work injury, and began to feel increas- seen by a psychologist and a family medicine ingly distressed and hopeless. His wife noted resident, JD was working as a farmhand to he was uncharacteristically irritable with her make ends meet. and the children, and that he had vivid night- mares and said he could smell ammonia. He What symptoms are typical of also had trouble keeping up his yard because Q anhydrous ammonia exposure? of the agitation and anxiety he experienced in approaching his workshed and equipment on the property. 710 The Journal of family PracTice | DECEMBER 2013 | Vol 62, no 12 Effects of ammonia exposure dia of the eye (cornea, lens, etc), the retina, or Ammonia is a water-soluble, colorless gas— the neural visual pathways. It may also have an alkaloid with a unique odor. In the past, a psychogenic component.5 Media-related most exposures were related to its use as a fer- causes of acute vision loss include keratitis tilizer, as was the case with JD. In recent years, or uveitis, edema of the cornea, blood in the it has also been used to illegally manufacture anterior chamber (hyphema), disturbance of methamphetamine, which has led to ammo- the lens, or hemorrhage into the vitreous.5,6 nia accidents and increased exposures.1-3 Retinal causes include occlusion of the cen- Systems commonly injured are the respi- tral retinal artery or vein, detachment of the ratory tract, ocular system, skin, and gastro- retina, or acute maculopathy.5-8 Neurologic intestinal tract (only if ingested).2 causes include injury to the optic nerve it- Ammonia destroys the mucosal barrier of self (normally monocular) or defects in the the respiratory tract, causing loss of cilia, edema, chiasmal or retrochiasmal regions (causing and smooth muscle contraction.3,4 Long-term partial loss in both eyes).5,9 If all of the above effects include chronic cough or hoarseness, possibilities have been ruled out, consider obstructive or restrictive airway disease, reac- psychogenic contribution to visual loss.5 Of- tive airway disease, or bronchiectasis.1,3 ten this diagnosis is called “functional vision The extent of ocular injury is related to loss,” which can include feigning visual loss the degree of ammonia exposure. In mild for secondary gain or subjective blindness as cases, there is eye irritation, increased tear is seen with a somatoform disorder (eg, con- When you production, a sensation of stinging or burn- version disorder). suspect a ing, and perhaps conjunctivitis or spasmodic JD had bilateral peripheral vision loss of somatoform winking. The patient may also experience both the medial and lateral visual fields with disorder, photophobia.1,3,4 In more severe cases, there macular sparing bilaterally. But he had an oth- including may be corneal ulcerations, iritis, anterior erwise normal physical examination. At this conversion, or posterior synechia, opacification of the point, the neurologist suspected conversion start therapy cornea, cataracts, glaucoma, atrophy of the disorder, while one ophthalmologist thought a and treat the retina, or severe pain.1,3 Blindness may occur, neuropathic disorder was responsible. symptoms as temporarily or permanently.4 This complete “real.” or partial vision loss is secondary to physical What is your working diagnosis damage that can be seen during an ophthal- Q for this patient’s symptoms? mologic examination.1,4 Skin injuries can range from a mild ery- thematous rash to a full thickness burn with bullae and even denudation.1 Long-term ef- fects include scarring or dermatitis.3 What are some of the Our patient had respiratory and skin Q psychological sequelae of symptoms that fit with classic ammonia ex- traumatic events such as the one posure (respiratory distress requiring in- this patient experienced? tubation, rash). His initial blindness was consistent with ammonia exposure; however, his subsequent peripheral loss was inconsis- tent with known reaction to ammonia. The neurologist had, early on, recognized What are some of the causes of that JD was significantly distressed by the ac- Q acute visual loss? cident and encouraged a psychological con- sultation. With the absence of identifiable ophthalmologic pathology, the patient reluc- tantly accepted this referral. The psychologist, aided by family medi- Causes of acute visual loss cine residents, entertained the diagnoses of Vision loss can be caused by injury to the me- Post-Traumatic Stress Disorder (PTSD) and JfPonline.com Vol 62, no 12 | DECEMBER 2013 | The Journal of family PracTice 711 somatoform disorders, particularly conversion. essary to begin treatment. When you suspect PTSD is unique among psychiatric diagnoses a somatoform disorder including conver- in that a patient must meet all 6 DSM V criteria:10 sion, start therapy and treat the symptoms as • exposure to a traumatic event involving ac- “real.”12 Tell the patient that no specific treat- tual or threatened death or serious injury ment will completely resolve the symptoms, • recollections, dreams, or hallucinations but that it can help.13 Whether the primary in which the trauma is re-experienced cause is neurologic or conversion based, • avoidance of stimuli associated with the there is often some spontaneous recovery of trauma vision that occurs between 2 weeks and 3 or • persistent symptoms of increased arous- more months.14 Peripheral field defects have al (eg, irritability, agitation) a guarded prognosis, although an extensive • symptoms and behavior that last for lon- rehabilitation program may improve the vi- ger than one month sion fields somewhat.15-18 • distress that is clinically significant. Conversion disorders effectively respond to cognitive behavioral therapy (CBT) includ- He met the criteria for a PTSD diagnosis ing gradual exposure to anxiety triggers.19 Re- and likely would benefit from treatment for it. habilitation for neurologic damage based on However, sensory loss related to PTSD alone remodeling of pathways responds to a similar would be unusual, perhaps as unusual as pe- gradual exercise or exposure to the lost func- CBT, including ripheral vision loss secondary to ammonia ex- tion. Since these interventions are similar gradual posure. Other factors needed to be explored. processes, a definitive diagnosis was unnec- exposure to Conversion disorders consist of disorders essary in JD’s case. A proprietary visual reha- anxiety triggers, of movement, such as seizures or paralysis, or bilitation therapy program is available17 that is effective both disorders of sensations, such as numbness or exposes the patient to visual field activity that for treating blindness. These may be episodic or sustained requires a cognitive reaction.15 This treatment conversion and have acute or chronic onset.11 facilitates recovery even into the sixth month disorders and Psychological factors are judged to be as- of therapy.16 However, the cost of the software for rehabilitating sociated with the symptom or deficit because is approximately $6000 and is not yet covered damaged conflicts or other stressors precede the initia- by insurance.15 neurologic tion or exacerbation of the symptom or deficit. JD could not afford the commercially pathways. This was possible in JD, but a degree of uncer- available programmed therapy. Therefore, we tainty lingered because he did not exhibit be- introduced an alternative treatment plan to havior typically seen with factitious disorder, challenge the transitional zone. With this plan, and performance anxiety could conceivably JD would play video games for 30 minutes at account for the outcome on his vision tests.